Apparatus used in pointing cannon



, UNITED STATES PATENT OFFICE.

! JOHN HOBDAY, OF PORTSMOUTH, VIRGINIA.

APPARATUS USED IN POINTING CANNON.

of the gun. The modes in which it may be Specification of Letters Patent No. 207, dated May 30, 1837.

fixed inits place are too numerousto dewhen from the effect of smoke, fog, or other To all whom it may concern Be it known that I, JOHN HOBDAY, of scribe, nor will a competent workman be at Portsmouth, in the county of Norfolk and any loss in this particular. In placing it State of Virginia, have invented a new and upon the trunnion, I have allowed a dove 5 useful Improvement in Apparatus Used for tailed, wedge-formed piece on one end of Pointing Cannon Either on Shipboard or the box, to fall into dovetailed grooves pre- Elsewhere; and I do hereby declare that pared for that purpose. To lessen the efi'ect the following is a full and exact description of the shock in firing, I interpose leather, or thereof, reference being had to the accomother elastic material, between the connect- 5 10 panying drawings. ing parts; or, if preferred, steel, or other I make a circular box, or drum, such as is springs may be employed. shown at A, in the accompanying drawing, In order to give a high degree of sensibiland within this I suspend, bypivots passing, ity to the pendulating index, it is desirable through the heads of the box, or drum, a that it should be suspended on small pivots, 70

weight which maybe semicircular, as shown or on fine points, or centers; but without at B, or in any form which may be presome provision to relieve such pivots, or

. ferred. This weight has attached to it an points, from the effect of the shock in firing,

index C, so placed upon it as that it shall they would soon be destroyed. This. susconstantly point horizontally from the axis pension, I, in general, effect in the following 75 of suspension. In the rim of the circular manner. Let F, F, be sections of the heads box, and also in one or both heads of it, of the drum, or ends of the box; G, G, be near its periphery, as at D andE, I make two elastic pieces of steel, attached tothe slots, or openings, which mayextend oneheads, near to their peripheries, the opposite fourth of the way round, so that the index ends covering the openings in the heads 3 may be exposed to view. On the edges of through which the gudgeons, or pivots, of

these openings I mark degrees, or make dithe axis, H, pass, which pivots are pointed, visions, which commence from the center of and pass into countersinks in the spring the openings, which center I make my 0,, or pieces, or are themselves countersunk to rezero, as it indicates the horizontal position ceive the points of pins, or screws, attached s5 of the gun, each way, from No. 1, upward. tothe spring pieces. The gudgeons, or This drum, or box, I attach to one of the pivots, are made large enough to sustain trunnions of the cannon in such a manner the shock, but do not quite touch the openthat the index shall point to 0, when the ings in the heads until brought into contact axis, or bore, of the gun is perfectly hori- -with' them by the effect of the firing; la 85 zontal. When so placed, it will be manifest stead of this arrangement, there may be a that any change in the direction of the axis knife blade suspension; and other arrangemay be read ofi by means of the index and ments maybe made, alike in principle, and, the divisions upon the openings on the consequently, producing the same effect. periphery and end of the box. To allow the In describing my invention, I have given 40 index, if necessary, to traverse beyond the such'anv arrangement of the respective parts openings, I enlarge the rim of the bix, formas I have believed to be most convenient, but ing the periphery, around its middle part." there may be many modifications thereof Although I have mentioned one of the, which would still leave it essentially the trunnions as the part of the gun upon which same. The box, for example, may be a seg- 45 I place the apparatus described, I do not ment of, instead of a whole circle; the susintend to confine myself in this particular, pension, also, may be made something like as it will give its indications equally well on that of the mariners compass, so that the any other part, and it may, probably, be instrument shall keep in a vertical position,

found in practice, more convenient to place notwithstanding the pitching and rolling 50 it elsewhere; the essential points in its apmotions of a vessel. The circular box may 7 plication, are to place it with the ends of be entirely omitted, such a frame, only,

the box vertically, and parallel to the axis being constructed as shall suffice to support of the gun, with the index so exposed as the pivots of the weight and index, and the that the gunner may have a full view of it divided scale. By the aid of this instru- 1 55 while he remains at his post, at the breech ment, a gun may be accurately pointed,

' causes, the view maybe interrupted, and

notwithstanding the motion produced by a heavy sea. 7 I

What I claim as my invention, and Wish to secure by Letters Patent, is

1. The constructing of an instrument for the pointing of cannon, which instrument has an index, pointing horizontally, or indicating the horizontal position and inclination of the gun to which it is attached, the position of the index being preserved by the action of a pendulous Weight to which it is attached, the whole constructed, and operating, substantially in the manner herein set forth.

2. I' also claim the manner of suspending the same as described, so as to combine the most perfect sensibility with the requisite degree of strength in the pivots.

J OHN HOBDAY.

Witnesses THOS. P. JONES, B. K. MORSELL. 

